Functional Transcranial Doppler (fTCD)

In 1996 I developed the first fully automated computer program for the analysis of functional Transcranial Doppler Sonography (fTCD) data for hemispheric lateralization of brain functions. This program – denoted as AVERAGE –  was published in the Journal of Neuroscience Methods a year later:

Deppe, M., Knecht, S., Henningsen, H., Ringelstein, E.B., 1997. AVERAGE: a Windows program for automated analysis of event related cerebral blood flow. J.Neurosci.Methods 75, 147-154.

To my knowledge, this was the first time that the term „fTCD“ was used in the peer-reviewed literature for the assessment of brain activity related cerebral blood flow changes. I chose the acronym „fTCD“ in analogy to functional Magnetic Resonance Imaging (fMRI). While fMRI provides mainly spatial information (in the range of millimeters) about the regional distribution of „brain activity“, fTCD can be considered as the temporal counterpart to fMRI – with a temporal resolution of about ten milliseconds. However, the spatial resolution of fTCD is (rather) limited to the supplying areas of the large brain vessels. In combination, fTCD and fMRI can be powerful tools to better understand the brain’s functional organization.

The AVERAGE software was the basis for hundreds of later fTCD studies on brain lateralization. AVERAGE is still in use in many labs and celebrates its twentieth anniversary this year! My own original papers about fTCD are listed below:

  1. Fisse, A.L., Pueschel, J., Deppe, M., Ringelstein, E.B., Ritter, M.A., 2016. TCD-Profiling Using AVERAGE. A New Technique to Evaluate Transcranial Doppler Ultrasound Flow Spectra of Subjects with Cerebral Small Vessel Disease. Cerebrovasc Dis 41, 50-59.
  2. Rosengarten, B., Deppe, M., Kaps, M., Klingelhofer, J., 2012. Methodological aspects of functional transcranial Doppler sonography and recommendations for simultaneous EEG recording. Ultrasound Med.Biol. 38, 989-996.
  3. Lohmann, H., Drager, B., Muller-Ehrenberg, S., Deppe, M., Knecht, S., 2005. Language lateralization in young children assessed by functional transcranial Doppler sonography. Neuroimage. 24, 780-790.
  4. Backer, M., Hammes, M., Sander, D., Funke, D., Deppe, M., Tolle, T.R., Dobos, G.J., 2004. Changes of cerebrovascular response to visual stimulation in migraineurs after repetitive sessions of somatosensory stimulation (acupuncture): a pilot study. Headache 44, 95-101.
  5. Deppe, M., Knecht, S., Lohmann, H., Ringelstein, E.B., 2004. A method for the automated assessment of temporal characteristics of functional hemispheric lateralization by transcranial Doppler sonography. J.Neuroimaging 14, 226-230.
  6. Deppe, M., Ringelstein, E.B., Knecht, S., 2004. The investigation of functional brain lateralization by transcranial Doppler sonography. Neuroimage. 21, 1124-1146.
  7. Lohmann, H., Deppe, M., Jansen, A., Schwindt, W., Knecht, S., 2004. Task repetition can affect functional magnetic resonance imaging-based measures of language lateralization and lead to pseudoincreases in bilaterality. J.Cereb.Blood Flow Metab 24, 179-187.
  8. Backer, M., Hammes, M.G., Valet, M., Deppe, M., Conrad, B., Tolle, T.R., Dobos, G., 2002. Different modes of manual acupuncture stimulation differentially modulate cerebral blood flow velocity, arterial blood pressure and heart rate in human subjects. Neurosci.Lett. 333, 203-206.
  9. Backer, M., Sander, D., Hammes, M.G., Funke, D., Deppe, M., Conrad, B., Tolle, T.R., 2001. Altered cerebrovascular response pattern in interictal migraine during visual stimulation. Cephalalgia 21, 611-616.
  10. Floel, A., Knecht, S., Lohmann, H., Deppe, M., Sommer, J., Drager, B., Ringelstein, E.B., Henningsen, H., 2001. Language and spatial attention can lateralize to the same hemisphere in healthy humans. Neurology 57, 1018-1024.
  11. Knecht, S., Drager, B., Floel, A., Lohmann, H., Breitenstein, C., Deppe, M., Henningsen, H., Ringelstein, E.B., 2001. Behavioural relevance of atypical language lateralization in healthy subjects. Brain 124, 1657-1665.
  12. Deppe, M., Knecht, S., Papke, K., Lohmann, H., Fleischer, H., Heindel, W., Ringelstein, E.B., Henningsen, H., 2000. Assessment of hemispheric language lateralization: a comparison between fMRI and fTCD. J.Cereb.Blood Flow Metab 20, 263-268.
  13. Drager, B., Floel, A., Deppe, M., Lohmann, H., Henningsen, H., Knecht, S., 2000. Association and dissociation of language dominance and handedness – possible impact on recovery from aphasia. Journal of Neurolinguistics 13, 279-282.
  14. Floel, A., Knecht, S., Sommer, J., Deppe, M., Lohmann, H., Drager, B., Henningsen, H., 2000. Functional significance of bilateral language dominance. Journal of Neurolinguistics 13, 286-289.
  15. Knecht, S., Deppe, M., Drager, B., Bobe, L., Lohmann, H., Ringelstein, E., Henningsen, H., 2000. Language lateralization in healthy right-handers. Brain 123 ( Pt 1), 74-81.
  16. Knecht, S., Drager, B., Deppe, M., Bobe, L., Lohmann, H., Floel, A., Ringelstein, E.B., Henningsen, H., 2000. Handedness and hemispheric language dominance in healthy humans. Brain 123 Pt 12, 2512-2518.
  17. Knecht, S., Drager, B., Deppe, M., Lohmann, M.H., Floel, A., Henningsen, H., 2000. Variability of the side and extent of language lateralization in the healthy population. Journal of Neurolinguistics 13, 297-300.
  18. Backer, M., Knecht, S., Deppe, M., Lohmann, H., Ringelstein, E.B., Henningsen, H., 1999. Cortical tuning: a function of anticipated stimulus intensity. Neuroreport 10, 293-296.
  19. Deppe, M., Knecht, S., Papke, K., Henningsen, H., Ringelstein, E.B., 1999. Functional TCD: Comparison with functional magnetic resonance imaging. Klinische Neurophysiologie 30, 292-298.
  20. Knecht, S., Deppe, M., Ringelstein, E.B., 1999. Determination of cognitive hemispheric lateralization by „functional“ transcranial Doppler cross-validated by functional MRI. Stroke 30, 2491-2492.
  21. Diehl, B., Knecht, S., Deppe, M., Young, C., Stodieck, S.R., 1998. Cerebral hemodynamic response to generalized spike-wave discharges. Epilepsia 39, 1284-1289.
  22. Knecht, S., Deppe, M., Ringelstein, E.B., Wirtz, M., Lohmann, H., Drager, B., Huber, T., Henningsen, H., 1998. Reproducibility of functional transcranial Doppler sonography in determining hemispheric language lateralization. Stroke 29, 1155-1159.
  23. Knecht, S., Deppe, M., Ebner, A., Henningsen, H., Huber, T., Jokeit, H., Ringelstein, E.B., 1998. Noninvasive determination of language lateralization by functional transcranial Doppler sonography: a comparison with the Wada test. Stroke 29, 82-86.
  24. Vollmer-Haase, J., Folkerts, H.W., Haase, C.G., Deppe, M., Ringelstein, E.B., 1998. Cerebral hemodynamics during electrically induced seizures. Neuroreport 9, 407-410.
  25. Deppe, M., Knecht, S., Henningsen, H., Ringelstein, E.B., 1997. AVERAGE: a Windows program for automated analysis of event related cerebral blood flow. J.Neurosci.Methods 75, 147-154.
  26. Knecht, S., Deppe, M., Backer, M., Ringelstein, E.B., Henningsen, H., 1997. Regional cerebral blood flow increases during preparation for and processing of sensory stimuli. Exp.Brain Res. 116, 309-314.
  27. Knecht, S., Henningsen, H., Deppe, M., Huber, T., Ebner, A., Ringelstein, E.B., 1996. Successive activation of both cerebral hemispheres during cued word generation. Neuroreport 7, 820-824.